Conventionally, wellhead connections to pressure control equipment are typically made by either a hand union or hammer union. Wellhead operators engaging or disengaging these conventional types of wellhead connections place themselves in danger of injury. The pressure control equipment to be connected to the wellhead is typically heavy, and remains suspended above the wellhead operator via use of a crane. Interacting with the crane operator, a technician at the wellhead below must struggle with the suspended load as it is lowered in order to achieve the proper entry angle into the wellhead to make a secure connection. The wellhead operator must then connect the wellhead to the pressure control equipment to the wellhead, typically via a bolted flanged connection. The bolts must be tightened manually by a person at the wellhead, typically via a “knock wrench” struck with a sledgehammer in order to get the bolts sufficiently tight to withstand the internal operating pressure. During this whole process, as noted, the operator is in physical danger of injuries, such as collision with the suspended pressure control equipment load, or pinched or crushed fingers and hands when securing the connection.
Wellhead operators are exposed to similar risks of injury during conventional removal of the pressure control equipment from the wellhead. The removal process is substantially the reverse of the engagement process described in the previous paragraph.
There is therefore a need in the well services industry to have a way to safely connect and disconnect pressure control equipment from the wellhead while minimizing the physical danger to human resources in the vicinity. The disclosed embodiments of high pressure seals for wellhead pressure control fittings are all hydraulically-actuated and -deactuated systems that lock pressure control equipment to the wellhead via a remote control station.